Saint Louis University (SLU) is an ideal environment for Kathleen W. Wyrwich, Ph.D., to continue to develop and apply new conceptual and methodological approaches to advance the use, understanding, interpretation, and evaluation of health-related quality of life (HRQoL) measures. Instruction on the use of many newer methodological tools that she needs to advance her range and ability to provide insightful and novel solutions to specific challenges in HRQoL measurement can be obtained there through graduate courses in Qualitative, Cluster, and Categorical Data Analyses, as well as Memory and Cognition. Furthermore, SLU provides a rich intellectual environment for collaborative interactions with graduate students and colleagues in diverse disciplines. The proposed career development and research plans couple new methodologies with current HRQoL measurement challenges in five areas. The first research challenge focuses on the three measures of HRQoL proposed in Healthy People 2010 as primary outcomes to monitor national progress in achieving health for all. Each of these measures, Self-Reported Health, Healthy Days, and Years of Healthy Life, provides distinct advantages in quantifying HRQoL, but little is known about their measurement properties. In both the general population and diverse U. S. subpopulations, Dr. Wyrwich will investigate and compare their measurement properties. The second, third, and fourth research challenges address the interpretation of the three Healthy People 2010 HRQoL measures. Using extant data, Dr. Wyrwich will: 1) establish critical values for categorizing the scoring ranges on these three HRQoL measures; 2) investigate the level of change over time that identifies an important improvement or decline on these HRQoL measures; and 3) develop crosswalk score estimation methods between these and other popular HRQoL population measures that facilitate score conversions. The fifth challenge she will address is an in-depth understanding of the cognitive processes that patients use when responding to questions that ask for retrospective judgments of their changes in HRQoL domains. Using cognitive interviews and hierarchical linear modeling, Dr. Wyrwich will qualitatively explore and quantitatively model the factors that affect patients? responses when making their global transition assessments. These development and research plans address several priority issues on the AHRQ research agenda including: strengthening quality measurement and improvement, especially among vulnerable populations; and providing patients, clinicians and other providers, purchasers, institutions, and public policymakers with the enhanced approaches to evaluate HRQoL outcomes.